In a Facebook post, the department said he is a 30-year veteran of the Jackson Police Department and previously served for 10 years as Chief of the Newburg Police Department. While the exact cause has not been definitively determined, investigators believe a propane tank may have contributed to the explosion. CEDARBURG, Wis. (CBS 58) — Two men were critically injured after an explosion destroyed a metal shed Saturday morning in Cedarburg. When deputies arrived, they found thick black smoke coming from a metal shed. The metal shed was destroyed.